Nine, without some background intelligence knowing which interface to defer to (and even them there will be some brief downtime), you cannot do this. Being connected to both means the IP stack has no idea which interface to send packets out to. This is all part of basic IP routing. You may (but even then it is doubtful) be able to do it if the networks are on separate subnets, but in a home use scenario I doubt you want to configure two routers.
Yeah, I definitely understand a brief amount of downtime--that completely makes sense, and I experience that with other OSes. In Windows or on other distros, I can be connected both to the LAN and WLAN at the same time, but I'm guessing that, by default, all traffic is sent out the LAN interface. If I unplug, i'll notice a very brief connectivity loss before traffic automatically is sent over the WLAN interface.
But I'm not trying to use
the two interfaces at once. Rather, what I'm saying is that in PCLOS, I can't simply even be connected
to both at the same time--even if traffic will be sent across only one. This means that the LAN interface is active and I'm plugged in, I can't just unplug and then have everything automatically switched over to the WLAN interface. Instead, I have to manually
either activate the WLAN interface or connect to a network on the WLAN interface. I can't have my wireless network connected and "waiting in the wings" so that I can "failover" or seamlessly move between LAN and WLAN connectivity.
Other OSes have a mechanism for handling this automatic switching, and I'm guessing that's the experience for most PCLOS users on here (or at least I hope!). I can't imagine that PCLOS laptop users here have to manually invoke their wireless connection when they unplug from the LAN connection...
So maybe it's a kernel issue like pinda suggested?